1. Field
Example embodiments relate to a method of forming a contact structure. Other example embodiments relate to a method of forming a contact structure electrically coupled between an upper conductor and a lower conductor through an insulator provided between the upper conductor and the lower conductor.
2. Description of the Related Art
In general, a semiconductor device may be classified as either a volatile memory device or a non-volatile memory device. Examples of the volatile memory device may include a dynamic random access memory (DRAM) device and a static random access memory (SRAM) device. Examples of the non-volatile memory device may include a read only memory (ROM) device and an electrically erasable programmable read only memory (EEPROM) device, e.g., a flash memory device.
The semiconductor devices may be commonly manufactured by performing a fabrication process for forming an electrical circuit on a silicon wafer used as a semiconductor substrate, an electrical die sorting (EDS) process for inspecting electrical characteristics of the semiconductor devices formed by the fabrication process, and a packaging process for packaging the semiconductor devices in epoxy resins and individuating the semiconductor devices.
The fabrication process may include a plurality of steps, e.g., a contact formation step. A photolithography process and an etching process may be performed in the contact formation process so that a contact structure electrically coupled between an upper conductor and a lower conductor may be formed through an insulating layer located between the lower conductor and the upper conductor.
As described above, the photolithography process and the etching process may be used in the contact formation process. A distance between contacts included in the contact structure may become narrower for forming the flash memory device that has an increased integration degree.
When the contacts of the flash memory device are formed by a conventional method, an electrical short may be generated between the contacts. Efficiently reducing the distance between the contacts may be difficult. A method of forming contacts capable of efficiently reducing a distance between the contacts becomes crucial to manufacture cutting-edge semiconductor devices.